AMD Radeon HD 6990 4 GB Review: Antilles Makes (Too Much) Noise : AMD?s Dual-Cayman Board Mashes The Gas
UPDATE:
Here's the gist from reading:
1. power rating breaks the 300w standard. This is rated at 375w.
2. Interestingly, it uses dual vBIOS like the other 6900 cards but with a twist. There is a switch to enable the 2nd vBIOS which boosts the core clock to 880Mhz @ 1.175V, but in turn makes it consume 450 watts!
3. In terms of performance, this thing blows everything out of the water. Not even close with the 580. Performance is on par with having two GTX 570s in SLI (around 5% less) but with better multi-monitor performance even compared to the GTX 580 due to having higher frame buffer.
4. Another interesting advancement is through tessilation. With tessilation turned 'ON', 76% of the performance is retained. This is better than the GTX 580 which sees 75% of performance retained.
5. Despite temperatures within acceptable range, the biggest problem is the Noise! This card is noisier than the GTX 480 by a big margin!
6. Again, while cooling is OK, the design is quite interesting. Two chambers are made to cool each gpu. What happens is: one chamber exits out the expansion slot (good), the other exits into your case (bad). Airflow becomes an issue within the case.
7. The size of the card is still 12" which is still similar to the 5970
8. There are 5 display outputs: (4) mini-dp and (1) D-Link DVI